This is a note to let you know that I've just added the patch titled
coresight: Fix memory leak in acpi_buffer->pointer
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
coresight-fix-memory-leak-in-acpi_buffer-pointer.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2768b5df3b7d4f1ce440c3f9d7cc5c840baad6a9
Author: Junhao He <hejunhao3@xxxxxxxxxx>
Date: Thu Aug 17 16:59:36 2023 +0800
coresight: Fix memory leak in acpi_buffer->pointer
[ Upstream commit 1a9e02673e2550f5612099e64e8761f0c8fc0f50 ]
There are memory leaks reported by kmemleak:
...
unreferenced object 0xffff00213c141000 (size 1024):
comm "systemd-udevd", pid 2123, jiffies 4294909467 (age 6062.160s)
hex dump (first 32 bytes):
04 00 00 00 02 00 00 00 18 10 14 3c 21 00 ff ff ...........<!...
00 00 00 00 00 00 00 00 03 00 00 00 10 00 00 00 ................
backtrace:
[<000000004b7c9001>] __kmem_cache_alloc_node+0x2f8/0x348
[<00000000b0fc7ceb>] __kmalloc+0x58/0x108
[<0000000064ff4695>] acpi_os_allocate+0x2c/0x68
[<000000007d57d116>] acpi_ut_initialize_buffer+0x54/0xe0
[<0000000024583908>] acpi_evaluate_object+0x388/0x438
[<0000000017b2e72b>] acpi_evaluate_object_typed+0xe8/0x240
[<000000005df0eac2>] coresight_get_platform_data+0x1b4/0x988 [coresight]
...
The ACPI buffer memory (buf.pointer) should be freed. But the buffer
is also used after returning from acpi_get_dsd_graph().
Move the temporary variables buf to acpi_coresight_parse_graph(),
and free it before the function return to prevent memory leak.
Fixes: 76ffa5ab5b79 ("coresight: Support for ACPI bindings")
Signed-off-by: Junhao He <hejunhao3@xxxxxxxxxx>
Reviewed-by: James Clark <james.clark@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Link: https://lore.kernel.org/r/20230817085937.55590-2-hejunhao3@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index c8940314cceb8..dbf508fdd8d16 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -494,19 +494,18 @@ static inline bool acpi_validate_dsd_graph(const union acpi_object *graph)
/* acpi_get_dsd_graph - Find the _DSD Graph property for the given device. */
static const union acpi_object *
-acpi_get_dsd_graph(struct acpi_device *adev)
+acpi_get_dsd_graph(struct acpi_device *adev, struct acpi_buffer *buf)
{
int i;
- struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
acpi_status status;
const union acpi_object *dsd;
status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL,
- &buf, ACPI_TYPE_PACKAGE);
+ buf, ACPI_TYPE_PACKAGE);
if (ACPI_FAILURE(status))
return NULL;
- dsd = buf.pointer;
+ dsd = buf->pointer;
/*
* _DSD property consists tuples { Prop_UUID, Package() }
@@ -557,12 +556,12 @@ acpi_validate_coresight_graph(const union acpi_object *cs_graph)
* returns NULL.
*/
static const union acpi_object *
-acpi_get_coresight_graph(struct acpi_device *adev)
+acpi_get_coresight_graph(struct acpi_device *adev, struct acpi_buffer *buf)
{
const union acpi_object *graph_list, *graph;
int i, nr_graphs;
- graph_list = acpi_get_dsd_graph(adev);
+ graph_list = acpi_get_dsd_graph(adev, buf);
if (!graph_list)
return graph_list;
@@ -663,22 +662,24 @@ static int acpi_coresight_parse_graph(struct device *dev,
struct acpi_device *adev,
struct coresight_platform_data *pdata)
{
+ int ret = 0;
int i, nlinks;
const union acpi_object *graph;
struct coresight_connection conn, zero_conn = {};
struct coresight_connection *new_conn;
+ struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
- graph = acpi_get_coresight_graph(adev);
+ graph = acpi_get_coresight_graph(adev, &buf);
/*
* There are no graph connections, which is fine for some components.
* e.g., ETE
*/
if (!graph)
- return 0;
+ goto free;
nlinks = graph->package.elements[2].integer.value;
if (!nlinks)
- return 0;
+ goto free;
for (i = 0; i < nlinks; i++) {
const union acpi_object *link = &graph->package.elements[3 + i];
@@ -686,17 +687,28 @@ static int acpi_coresight_parse_graph(struct device *dev,
conn = zero_conn;
dir = acpi_coresight_parse_link(adev, link, &conn);
- if (dir < 0)
- return dir;
+ if (dir < 0) {
+ ret = dir;
+ goto free;
+ }
if (dir == ACPI_CORESIGHT_LINK_MASTER) {
new_conn = coresight_add_out_conn(dev, pdata, &conn);
- if (IS_ERR(new_conn))
- return PTR_ERR(new_conn);
+ if (IS_ERR(new_conn)) {
+ ret = PTR_ERR(new_conn);
+ goto free;
+ }
}
}
- return 0;
+free:
+ /*
+ * When ACPI fails to alloc a buffer, it will free the buffer
+ * created via ACPI_ALLOCATE_BUFFER and set to NULL.
+ * ACPI_FREE can handle NULL pointers, so free it directly.
+ */
+ ACPI_FREE(buf.pointer);
+ return ret;
}
/*
